<?php if(!defined('BASEPATH')) exit('No direct script access allowed');
/**
* Ignited Datatables
*
* This is a wrapper class/library based on the native Datatables server-side implementation by Allan Jardine
* found at http://datatables.net/examples/data_sources/server_side.html for CodeIgniter
*
* @package CodeIgniter
* @subpackage libraries
* @category library
* @version 0.7
* @author Vincent Bambico <metal.conspiracy@gmail.com>
* Yusuf Ozdemir <yusuf@ozdemir.be>
* @link http://codeigniter.com/forums/viewthread/160896/
*/
class Datatables
{
	/**
	* Global container variables for chained argument results
	*
	*/
	protected $ci;
	protected $table;
	protected $distinct;
	protected $group_by;
	protected $select = array();
	protected $joins = array();
	protected $columns = array();
	protected $where = array();
	protected $filter = array();
	protected $add_columns = array();
	protected $edit_columns = array();
	protected $unset_columns = array();
	protected $order_by = array();

	/**
	* Copies an instance of CI
	*/
	public function __construct()
	{
		$this->ci =& get_instance();
	}

	/**
	* If you establish multiple databases in config/database.php this will allow you to
	* set the database (other than $active_group) - more info: http://codeigniter.com/forums/viewthread/145901/#712942
	*/
	public function set_database($db_name)
	{
		$db_data = $this->ci->load->database($db_name, TRUE);
		$this->ci->db = $db_data;
	}

	/**
	* Generates the SELECT portion of the query
	*
	* @param string $columns
	* @param bool $backtick_protect
	* @return mixed
	*/
	public function select($columns, $backtick_protect = TRUE)
	{
		foreach($this->explode(',', $columns) as $val)
		{
			$column = trim(preg_replace('/(.*)\s+as\s+(\w*)/i', '$2', $val));
			$this->columns[] = $column;
			$this->select[$column] = trim(preg_replace('/(.*)\s+as\s+(\w*)/i', '$1', $val));
		}

		$this->ci->db->select($columns, $backtick_protect);
		return $this;
	}

	/**
	* Generates the DISTINCT portion of the query
	*
	* @param string $column
	* @return mixed
	*/
	public function distinct($column)
	{
		$this->distinct = $column;
		$this->ci->db->distinct($column);
		return $this;
	}

	/**
	* Generates the GROUP_BY portion of the query
	*
	* @param string $column
	* @return mixed
	*/
	public function group_by($column)
	{
		$this->group_by = $column;
		$this->ci->db->group_by($column);
		return $this;
	}

	/**
	* Generates the FROM portion of the query
	*
	* @param string $table
	* @return mixed
	*/
	public function from($table)
	{
		$this->table = $table;
		$this->ci->db->from($table);
		return $this;
	}

	/**
	* Generates the JOIN portion of the query
	*
	* @param string $table
	* @param string $fk
	* @param string $type
	* @return mixed
	*/
	public function join($table, $fk, $type = NULL)
	{
		$this->joins[] = array($table, $fk, $type);
		$this->ci->db->join($table, $fk, $type);
		return $this;
	}

	/**
	* Generates the WHERE portion of the query
	*
	* @param mixed $key_condition
	* @param string $val
	* @param bool $backtick_protect
	* @return mixed
	*/
	public function where($key_condition, $val = NULL, $backtick_protect = TRUE)
	{
		$this->where[] = array($key_condition, $val, $backtick_protect);
		$this->ci->db->where($key_condition, $val, $backtick_protect);
		return $this;
	}

	/**
	* Generates the WHERE portion of the query
	*
	* @param mixed $key_condition
	* @param string $val
	* @param bool $backtick_protect
	* @return mixed
	*/
	public function or_where($key_condition, $val = NULL, $backtick_protect = TRUE)
	{
		$this->where[] = array($key_condition, $val, $backtick_protect);
		$this->ci->db->or_where($key_condition, $val, $backtick_protect);
		return $this;
	}

	/**
	* Generates the WHERE portion of the query
	*
	* @param mixed $key_condition
	* @param string $val
	* @param bool $backtick_protect
	* @return mixed
	*/
	public function like($key_condition, $val = NULL, $backtick_protect = TRUE)
	{
		$this->where[] = array($key_condition, $val, $backtick_protect);
		$this->ci->db->like($key_condition, $val, $backtick_protect);
		return $this;
	}

	/**
	* Generates the WHERE portion of the query
	*
	* @param mixed $key_condition
	* @param string $val
	* @param bool $backtick_protect
	* @return mixed
	*/
	public function filter($key_condition, $val = NULL, $backtick_protect = TRUE)
	{
		$this->filter[] = array($key_condition, $val, $backtick_protect);
		return $this;
	}

	/**
	* Sets additional column variables for adding custom columns
	*
	* @param string $column
	* @param string $content
	* @param string $match_replacement
	* @return mixed
	*/
	public function add_column($column, $content, $match_replacement = NULL)
	{
		$this->add_columns[$column] = array('content' => $content, 'replacement' => $this->explode(',', $match_replacement));
		return $this;
	}

	/**
	* Sets additional column variables for editing columns
	*
	* @param string $column
	* @param string $content
	* @param string $match_replacement
	* @return mixed
	*/
	public function edit_column($column, $content, $match_replacement)
	{
		$this->edit_columns[$column][] = array('content' => $content, 'replacement' => $this->explode(',', $match_replacement));
		return $this;
	}

	/**
	* Unset column
	*
	* @param string $column
	* @return mixed
	*/
	public function unset_column($column)
	{
		$this->unset_columns[] = $column;
		return $this;
	}

	/**
	* Builds all the necessary query segments and performs the main query based on results set from chained statements
	*
	* @param string charset
	* @return string
	*/
	public function generate($charset = 'UTF-8')
	{
		$this->get_paging();
		$this->get_ordering();
		$this->get_filtering();
		return $this->produce_output($charset);
	}

	/**
	* Generates the LIMIT portion of the query
	*
	* @return mixed
	*/
	protected function get_paging()
	{
		$iStart = $this->ci->input->post('iDisplayStart');
		$iLength = $this->ci->input->post('iDisplayLength');
		$this->ci->db->limit(($iLength != '' && $iLength != '-1')? $iLength : 100, ($iStart)? $iStart : 0);
	}

	/**
	* Generates the ORDER BY portion of the query
	*
	* @return mixed
	*/
	protected function get_ordering()
	{
		if($this->check_mDataprop())
			$mColArray = $this->get_mDataprop();
		elseif($this->ci->input->post('sColumns'))
			$mColArray = explode(',', $this->ci->input->post('sColumns'));
		else
			$mColArray = $this->columns;

		$mColArray = array_values(array_diff($mColArray, $this->unset_columns));
		$columns = array_values(array_diff($this->columns, $this->unset_columns));

		for($i = 0; $i < intval($this->ci->input->post('iSortingCols')); $i++)
			if(isset($mColArray[intval($this->ci->input->post('iSortCol_' . $i))]) && in_array($mColArray[intval($this->ci->input->post('iSortCol_' . $i))], $columns) && $this->ci->input->post('bSortable_'.intval($this->ci->input->post('iSortCol_' . $i))) == 'true')
		  		$this->ci->db->order_by($mColArray[intval($this->ci->input->post('iSortCol_' . $i))], $this->ci->input->post('sSortDir_' . $i));
	}

	/**
	* Generates the LIKE portion of the query
	*
	* @return mixed
	*/
	protected function get_filtering()
	{
		if($this->check_mDataprop())
			$mColArray = $this->get_mDataprop();
		elseif($this->ci->input->post('sColumns'))
			$mColArray = explode(',', $this->ci->input->post('sColumns'));
		else
			$mColArray = $this->columns;

		$sWhere = '';
		$sSearch = mysql_real_escape_string($this->ci->input->post('sSearch'));
		$mColArray = array_values(array_diff($mColArray, $this->unset_columns));
		$columns = array_values(array_diff($this->columns, $this->unset_columns));

		if($sSearch != '')
			for($i = 0; $i < count($mColArray); $i++)
		  		if($this->ci->input->post('bSearchable_' . $i) == 'true' && in_array($mColArray[$i], $columns))
		    		$sWhere .= $this->select[$mColArray[$i]] . " LIKE '%" . $sSearch . "%' OR ";

		$sWhere = substr_replace($sWhere, '', -3);

		if($sWhere != '')
			$this->ci->db->where('(' . $sWhere . ')');

		for($i = 0; $i < intval($this->ci->input->post('iColumns')); $i++)
		{
			if(isset($_POST['sSearch_' . $i]) && $this->ci->input->post('sSearch_' . $i) != '' && in_array($mColArray[$i], $columns))
			{
				$miSearch = explode(',', $this->ci->input->post('sSearch_' . $i));

				foreach($miSearch as $val)
				{
					if(preg_match("/(<=|>=|=|<|>)(\s*)(.+)/i", trim($val), $matches))
					  $this->ci->db->where($this->select[$mColArray[$i]].' '.$matches[1], $matches[3]);
					else
					  $this->ci->db->where($this->select[$mColArray[$i]].' LIKE', '%'.$val.'%');
				}
			}
		}

		foreach($this->filter as $val)
		$this->ci->db->where($val[0], $val[1], $val[2]);
	}

	/**
	* Compiles the select statement based on the other functions called and runs the query
	*
	* @return mixed
	*/
	protected function get_display_result()
	{
		$data = $this->ci->db->get();
		return $data;
	}

	/**
	* Builds a JSON encoded string data
	*
	* @param string charset
	* @return string
	*/
	protected function produce_output($charset)
	{
		$aaData = array();
		$rResult = $this->get_display_result();
		$iTotal = $this->get_total_results();
		$iFilteredTotal = $this->get_total_results(TRUE);

		foreach($rResult->result_array() as $row_key => $row_val)
		{
			$aaData[$row_key] = ($this->check_mDataprop())? $row_val : array_values($row_val);

			foreach($this->add_columns as $field => $val)
				if($this->check_mDataprop())
					$aaData[$row_key][$field] = $this->exec_replace($val, $aaData[$row_key]);
				else
				$aaData[$row_key][] = $this->exec_replace($val, $aaData[$row_key]);

			foreach($this->edit_columns as $modkey => $modval)
				foreach($modval as $val)
				$aaData[$row_key][($this->check_mDataprop())? $modkey : array_search($modkey, $this->columns)] = $this->exec_replace($val, $aaData[$row_key]);

				$aaData[$row_key] = array_diff_key($aaData[$row_key], ($this->check_mDataprop())? $this->unset_columns : array_intersect($this->columns, $this->unset_columns));

				if(!$this->check_mDataprop())
				$aaData[$row_key] = array_values($aaData[$row_key]);
		}

		$sColumns = array_diff($this->columns, $this->unset_columns);
		$sColumns = array_merge_recursive($sColumns, array_keys($this->add_columns));

		$sOutput = array
		(
		'sEcho' => intval($this->ci->input->post('sEcho')),
		'iTotalRecords' => $iTotal,
		'iTotalDisplayRecords' => $iFilteredTotal,
		'aaData' => $aaData,
		'sColumns' => implode(',', $sColumns)
		);

		if(strtolower($charset) == 'utf-8')
			return json_encode($sOutput);
		else
			return $this->jsonify($sOutput);
	}

	/**
	* Get result count
	*
	* @return integer
	*/
	protected function get_total_results($filtering = FALSE)
	{
		if($filtering)
		$this->get_filtering();

		foreach($this->joins as $val)
		$this->ci->db->join($val[0], $val[1], $val[2]);

		foreach($this->where as $val)
		$this->ci->db->where($val[0], $val[1], $val[2]);

		return $this->ci->db->count_all_results($this->table);
	}

	/**
	* Runs callback functions and makes replacements
	*
	* @param mixed $custom_val
	* @param mixed $row_data
	* @return string $custom_val['content']
	*/
	protected function exec_replace($custom_val, $row_data)
	{
	  	$replace_string = '';

		if(isset($custom_val['replacement']) && is_array($custom_val['replacement']))
		{
			foreach($custom_val['replacement'] as $key => $val)
			{
			  	$sval = preg_replace("/(?<!\w)([\'\"])(.*)\\1(?!\w)/i", '$2', trim($val));

				if(preg_match('/(\w+)\((.*)\)/i', $val, $matches) && function_exists($matches[1]))
				{
					$func = $matches[1];
					$args = preg_split("/[\s,]*\\\"([^\\\"]+)\\\"[\s,]*|" . "[\s,]*'([^']+)'[\s,]*|" . "[,]+/", $matches[2], 0, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);

					foreach($args as $args_key => $args_val)
					{
						$args_val = preg_replace("/(?<!\w)([\'\"])(.*)\\1(?!\w)/i", '$2', trim($args_val));
						$args[$args_key] = (in_array($args_val, $this->columns))? ($row_data[($this->check_mDataprop())? $args_val : array_search($args_val, $this->columns)]) : $args_val;
					}

					$replace_string = call_user_func_array($func, $args);
				}
			  	elseif(in_array($sval, $this->columns))
			    	$replace_string = $row_data[($this->check_mDataprop())? $sval : array_search($sval, $this->columns)];
			  	else
			    	$replace_string = $sval;

			  	$custom_val['content'] = str_ireplace('$' . ($key + 1), $replace_string, $custom_val['content']);
			}
		}

	  	return $custom_val['content'];
	}

	/**
	* Check mDataprop
	*
	* @return bool
	*/
	protected function check_mDataprop()
	{
		if(!$this->ci->input->post('mDataProp_0'))
			return FALSE;

		for($i = 0; $i < intval($this->ci->input->post('iColumns')); $i++)
			if(!is_numeric($this->ci->input->post('mDataProp_' . $i)))
		return TRUE;

	  	return FALSE;
	}

	/**
	* Get mDataprop order
	*
	* @return mixed
	*/
	protected function get_mDataprop()
	{
		$mDataProp = array();

		for($i = 0; $i < intval($this->ci->input->post('iColumns')); $i++)
		$mDataProp[] = $this->ci->input->post('mDataProp_' . $i);

		return $mDataProp;
	}

	/**
	* Return the difference of open and close characters
	*
	* @param string $str
	* @param string $open
	* @param string $close
	* @return string $retval
	*/
	protected function balanceChars($str, $open, $close)
	{
		$openCount = substr_count($str, $open);
		$closeCount = substr_count($str, $close);
		$retval = $openCount - $closeCount;
		return $retval;
	}

	/**
	* Explode, but ignore delimiter until closing characters are found
	*
	* @param string $delimiter
	* @param string $str
	* @param string $open
	* @param string $close
	* @return mixed $retval
	*/
	protected function explode($delimiter, $str, $open = '(', $close=')')
	{
		$retval = array();
		$hold = array();
		$balance = 0;
		$parts = explode($delimiter, $str);

		foreach($parts as $part)
		{
			$hold[] = $part;
			$balance += $this->balanceChars($part, $open, $close);

			if($balance < 1)
			{
				$retval[] = implode($delimiter, $hold);
				$hold = array();
				$balance = 0;
			}
		}

		if(count($hold) > 0)
		$retval[] = implode($delimiter, $hold);

		return $retval;
	}

	/**
	* Workaround for json_encode's UTF-8 encoding if a different charset needs to be used
	*
	* @param mixed result
	* @return string
	*/
	protected function jsonify($result = FALSE)
	{
		if(is_null($result))
		return 'null';

		if($result === FALSE)
		return 'false';

		if($result === TRUE)
		return 'true';

		if(is_scalar($result))
		{
			if(is_float($result))
				return floatval(str_replace(',', '.', strval($result)));

			if(is_string($result))
			{
				static $jsonReplaces = array(array('\\', '/', '\n', '\t', '\r', '\b', '\f', '"'), array('\\\\', '\\/', '\\n', '\\t', '\\r', '\\b', '\\f', '\"'));
				return '"' . str_replace($jsonReplaces[0], $jsonReplaces[1], $result) . '"';
			}
			else
			  	return $result;
		}

		$isList = TRUE;

		for($i = 0, reset($result); $i < count($result); $i++, next($result))
		{
			if(key($result) !== $i)
			{
			  	$isList = FALSE;
			  	break;
			}
		}

		$json = array();

		if($isList)
		{
			foreach($result as $value)
		  	$json[] = $this->jsonify($value);

			return '[' . join(',', $json) . ']';
		}
		else
		{
			foreach($result as $key => $value)
			  $json[] = $this->jsonify($key) . ':' . $this->jsonify($value);

			return '{' . join(',', $json) . '}';
		}
	}
}